The invention lies in the field of washing appliances. The invention relates to a front-loading washing machine with a laundry container mounted in a floating manner through a shaft within a bearing sleeve fixed to the rear wall of the tub, and driven by a motor disposed behind the rear wall of the tub.
German Published, Non-Prosecuted Patent Application DE 195 47 745 A1, corresponding to U.S. Pat. No. 5,894,746 to Skrippek and U.S. Pat. No. 5,862,686 to Skrippek, discloses such a drive device. In the drive device, the horizontally located shaft of the laundry container is connected to the rotor of the motor in a rotationally fixed manner at its outer end. Thus, the motor directly drives the shaft of the laundry container. Because the motor drives the laundry container directly, it has to apply a comparatively high torque to cause the container to move.
German Published, Non-Prosecuted Patent Application DE 39 27 426 A1 discloses a direct-current external-rotor motor for directly driving a laundry container in a laundry-treatment machine and of which the rotor drives the drive shaft of the laundry container through a gear mechanism, for example, a planetary gear mechanism. Because the gear mechanism is it provided between the motor and the rear wall of the washing machine, additional space is required, which is then not available for the laundry container.
Luxemburg Patent Application LU 37 211 discloses an electric drive motor fastened on an oscillating housing through a carrying arm and drives a belt pulley of a tub through transmission belts. British Patent No. GB 2 104 110 A discloses a drive motor fastened outside the periphery of a 354 158 A2, corresponding to U.S. Pat. No. 4,914,331 to Lewis, also disclose drive motors intended for driving laundry containers mounted in tubs and that are disposed behind the rear wall of the tub, but are not connected to the rear wall of the tub.
It is accordingly an object of the invention to provide a front-loading washing machine that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that improves a front-loading washing machine such that the motor is disposed in a space-saving manner.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a front-loading washing machine including a tub having a rear wall with an inside surface, an outside surface, and a center, a bearing sleeve connected to the rear wall, a shaft disposed in the bearing sleeve and at the center of the rear wall, a motor connected to the outside surface of the rear wall at a distance from the center of the rear wall, the motor producing a torque, a gear mechanism connected to the shaft and to the motor, the gear mechanism transmitting the torque produced by the motor to the shaft, and a laundry container mounted in a floating manner to the bearing sleeve through the shaft, the laundry container driven by the motor.
The objectives are achieved according to the invention in that the motor is disposed on the rear wall itself outside the center of the rear wall, the center being formed by the shaft, and in that the torque produced by the motor can be transmitted to the shaft through a gear mechanism.
A particular advantage of the invention is that a motor that, in comparison with direct driving, has a lower torque drives the laundry container. The torque is reduced by a gear mechanism that, nevertheless, in contrast to a motor disposed concentrically to the drive shaft and an associated, likewise concentrically disposed gear mechanism, as is disclosed in German Published, Non-Prosecuted Patent Application DE 39 27 426 A1, results in a reduction in the installation space required for the drive.
Particularly advantageous in the case of the drive according to the invention is that the motor requires lower outlay in terms of materials than direct-drive motors. Moreover, for the drive according to the invention, the tolerances in the air gap can be better controlled than in the case of direct driving. Such control has a favorable effect on the machine efficiency and the motor noise.
In accordance with another feature of the invention, there is provided a carrier part connecting the motor to the outside surface of the rear wall, the carrier part being connected to the outside surface of the rear wall. Preferably, the carrier part directly connects the motor to the rear wall.
In accordance with a further feature of the invention, the bearing sleeve is fixed to the rear wall.
In accordance with an added feature of the invention, the carrier part has a carrier arm with a cup-like widened section housing the motor.
A further advantage of the invention is that the motor is disposed either on the rear wall itself or on the carrying part. The carrying part is formed, for example, by arms extending outward from the center formed by the laundry-container shaft, with the motor being disposed on one of the arms. The motor-bearing arm is preferably widened in the form of a circle in the same plane as the rear wall of the tub. As a result, in a plan view of the rear wall of the tub and of the carrying star, the motor extends in its entirety in the region of a carrying arm of the carrying part. The carrying part preferably has a U-shaped profile that is oriented away from the rear wall of the tub and gives it a higher level of rigidity. The U-shaped profile preferably also encloses the circular convexity in the motor-accommodating carrying arm. In another exemplary embodiment, the U-shaped profile for accommodating the motor is directed toward the rear wall of the tub.
In accordance with an additional feature of the invention, if the laundry container has a filling opening inclined upward, then the motor is disposed beneath the shaft in a region between the tub rear wall and a rear wall of the washing machine.
The motor according to the invention is particularly advantageously used when the laundry container and the tub accommodating it are disposed in the washing machine with a slight inclination, for example, approximately 10xc2x0 or 15xc2x0, in relation to the horizontal, with the front side of the tub, which is provided with the filling opening, being located at a higher level than the rear wall. In such a case, the motor is disposed beneath the laundry-container shaft. As a result, the top edge of the rear wall of the tub is located in the vicinity of the rear wall of the washing-machine housing and, beneath the laundry-container shaft, which is located in the center of the rear wall of the tub, there is sufficient space between the rear wall of the tub and the rear wall of the housing to accommodate the motor.
In accordance with yet another feature of the invention, the carrier part has a carrier side directed away from the rear wall and the motor is disposed on the carrier side.
In accordance with yet a further feature of the invention, the motor is disposed on the carrier part in a region between the carrier part and the rear wall.
In accordance with yet an added feature of the invention, the motor has a motor shaft, a pulley is connected to the motor shaft, a belt is connected to the pulley and to the shaft, and the motor drives the shaft through the belt and the pulley.
In accordance with yet an additional feature of the invention, the shaft has a shaft pulley and the belt is disposed around the shaft pulley.
In accordance with again another feature of the invention, the shaft has a bell-like flange and the belt is disposed around the flange.
Possible gear mechanisms include a toothed belt or a V-belt in conjunction with corresponding belt pulleys or a toothed gear mechanism, in particular, with helically toothed gearwheels. It is also possible to use a chain to transmit the movement from a pinion provided on the motor shaft to a chain wheel provided on the laundry-container shaft.
In accordance with again a further feature of the invention, the belt is one of a V-belt, a toothed belt, and V-ribbed belt.
In accordance with again an added feature of the invention, the gear mechanism has gearwheels and the gearwheels drive the shaft.
In accordance with again an additional feature of the invention, the motor is an external-rotor motor. The stator cores and the magnetic poles of the rotor are disposed either axially or radially in relation to one another.
In accordance with still another feature of the invention, the motor has stator cores and the carrier part has a flange forming a bearing sleeve of the motor shaft and bearing the stator cores.
In accordance with still a further feature of the invention, the motor has magnetic poles and the stator cores and the magnetic poles of the motor are located opposite one another in an axial or direction with respect to the motor shaft.
In accordance with still an added feature of the invention, the motor has a rotor and the rear wall or carrier part has an annular-shaped side wall surrounding the rotor.
In accordance with still an additional feature of the invention, the motor has a rotor shaped as a bell-like flange.
In accordance with a concomitant feature of the invention, the motor is an electronically commutated direct-current motor, an asynchronous motor controlled by a frequency converter, or a reluctance motor.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a front-loading washing machine, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.